This application relates to optical fibers and fiber devices, and more specifically, to devices coupled to fibers with angle-polished facets.
Optical fibers are widely used in transmission and delivery of optical signals from one location to another in a variety of optical devices and systems. A typical fiber includes a high-index fiber core and a low-index cladding layer surrounding the fiber core to form an optical waveguide and to guide the optical energy along the fiber core. Such a fiber may be used to carry an optical signal at a single wavelength or multiple optical signals at different wavelengths.
The end facet of a fiber may be fabricated in two different configurations. In one configuration, the end facet is substantially perpendicular to the fiber core. An optical signal propagating along the fiber core, when exiting such an end facet, usually does not significantly deviates from the longitudinal direction of the fiber core. However, the end facet can cause optical reflection which may adversely interfere with the optical signals or affect a device that receives such reflection. To mitigate this problem, the end facet may be polished to form an acute angle with respect to the longitudinal direction of the fiber core. This angle-polished facet still reflects light but at a direction different from the optical signals along the fiber core. Hence, the reflected light generally does not interfere with a signal along the fiber core.
The devices of the present disclosure are designed in part to couple with one or more fibers that are angle-polished to reduce the adverse effects of optical reflection. Each fiber is mounted so that the longitudinal direction of the fiber core forms an angle with respect to an optical axis of a device along which an optical beam is coupled to or from the angle-polished end facet of the fiber.